No one stepping for the first time into a room made of books can know instinctively how to behave, what is expected, what is promised, what is allowed. One may be overcome by horror--at the cluster or the vastness, the stillness, the mocking reminder of everything one doesn't know, the surveillance--and some of that overwhelming feeling may cling on, even after the rituals and conventions are learned, the geography mapped, and the natives found friendly.